NORFOLK, Va. (WAVY) — A former lieutenant in the Chesapeake Fire Department pleaded guilty Tuesday to charges of coercing and enticing a minor to engage in illegal sexual activity.

Court documents say 50-year-old Thomas W. Almberg, of Virginia Beach, frequented several social media sites looking for teenage girls to chat with. In January, he met a 15-year-old boy pretending to be a 16-year-old girl on an interactive video game, Clash of Clans. The two began chatting and text messaging. Over the next two months, they exchanged over 8,000 text messages. Court documents say the conversations quickly grew to be sexually graphic.

In April, Almberg met a 16-year-old girl on a different mobile chat application. Their conversation also became sexual in nature, and they exchanged sexually explicit photos. Earlier this year, in May, Almberg went to the girl’s workplace in Elizabeth City, North Carolina, where he propositioned her for sex. She declined, he left and was taken into custody shortly after.

Almberg was charged by criminal information on October 12. He faces a mandatory minimum penalty of 10 years in prison and a maximum penalty of life in prison. He’s set to be sentenced in January 2017.

Chesapeake officials say as of October 6, Almberg is no longer employed with the city.